发电机运行中轴电压测试技术误区及改进方法

Technical Error and Improvement of Shaft Voltage Measurement in Operation of Large Turbo-Generator

现有标准体系中未对发电机运行中轴电压测试进行明确规定,现场测试时存在技术误区,测试方法的错误会给机组运行带来人为制造的风险和不良后果,因运行中轴电压测试技术误区及不良后果引发的发电机故障时有发生。本文在分析发电机轴电压测试相关标准的基础上,结合现场故障案例,指出了运行中测试发电机轴电压的技术误区及不足,提出了一种新的改进测试方法。通过现场实测,证明新的测试方法可以达到既满足标准规程中检查发电机轴电压及励端轴承座绝缘的目的,又不会出现因测试时的技术误区所带来的风险和不良后果。

In the existing standard system,shaft voltage test for generator in running state is not clearly specified,and there are technical errors in the field test.The error of the test method will bring artificial risks and adverse consequences to the generator,the generator failure caused by the technical errors and the adverse consequences of shaft voltage test for generator in running state occur from time to time.On the basis of analyzing the relative standard of generator shaft voltage test and combining with the field fault case,this paper points out the technical errors and shortcomings of shaft voltage test for generator in operation,and puts forward a new improved test method.Through field measurement,it is proved that the new test method can not only meet the purpose of shaft voltage test for generator and the insulation of the bearing block at the excitation end,but also avoid the risks and adverse consequences caused by technical errors in the test.